1. Field of the Invention
The present invention relates generally to a strobe apparatus for strobe photographing, and one which is particularly suitable for adaptation in close-up photographing where parallax of light angle is a problem, and one which is also suitable for photographing using both bounced light and partially direct light.
2. Description of the Prior Art
Hitherto, it has been known that in a general strobe apparatus mounted on an ordinary still camera for photographing, the range of flashed light from the strobe apparatus and range of photographing angle are of the relation as shown in FIG. 1. The range of dotted lines shows the angle range of the flashed light by the strobe apparatus 1 and the angle range shown by solid lines is of the photographing angle of the camera 2. As shown in FIG. 1, since the optical axis of the photographic lens 21 and the optical axis of the flash apparatus 1 are apart by a distance H, parallax between the flashing angle and the photographing angle exists, and it becomes a more severe problem when the distance from the camera to the object is smaller and when the distance H between the lens center and the center of the flash light is the larger.
When the two angle ranges, that is, flash light angle and photographing angle differ from each other, there is produced an insufficiently illuminated part of the photographic object when photographed, and this problem is generally called parallax of light. To describe more in detail, provided that when the distance between the camera and the photographic object is as small as D.sub.1, a part O-O' of the objective scenery is not illuminated by the flash light from the strobe apparatus 1, and when the distance is larger as shown by D.sub.2, then the smaller part P-P' of the objective scenery only is out of illumination by the flash light.
In order to overcome the above-mentioned problem, recently several devices have been proposed. A first proposed device is shown in FIG. 2(a), wherein the optical axis of a strobe apparatus, determined by relative spatial relation between the strobe lamp 4 and a reflex mirror 3, is fixedly tilted. That is, the optical axis of this strobe apparatus is permanently downwardly tilted to an axis l.sub.3 which is tilted by an angle x.degree. from the normal optical axis l.sub.1 of an ordinary strobe apparatus, by mounting the reflex mirror in a tilted position with respect to a casing 5.
Another proposal is that, in a bounce light strobe apparatus as shown in FIG. 2(b), on top of a known mechanism for bounce flashing, that is a head rotation mechanism, a further mechanism is added to select the optical axis at a slightly downward tilted position l.sub.3 from the ordinary position l.sub.1. By such means, an x.degree. downward tilting is possible.
The device shown in FIG. 2(a) can be realized at a relatively cheap cost; but this apparatus has a poor efficiency since a part of the flash light is lost by the lower end of the opening part of the casing 5 and the lower end of the optical panel 6, and moreover, since there is a gap between the front end of the reflection mirror 3 and the optical panel 6 the appearance of the front lower part of the flash apparatus is not satisfactorily neat. Furthermore, since the optical axis of the flash apparatus is tilted downward there may be an undesirable parallax between the flash light angle and the photographic angle for long distance photographing.
On the other hand, in the hitherto-proposed apparatus of FIG. 2(b), since the small downward tilting angle is given by downward tilting of the movable head part, a small downward tilting from the normal operation angle requires a complicated configuration, hence an increase of manufacturing cost, and also a problem of the mechanical strength at the pivotting part cannot be disregarded. Furthermore, the configuration of FIG. 2(b) requires a structure of pivotted movable tilted angle which is common with the expensive bounce type flashing apparatus. Accordingly, for a small type flash apparatus where no bounce flashing is necessary the configuration is not suitable in view of higher cost of manufacture. Besides, for a small type flash apparatus, the small angle adjustment necessary for parallax compensation can not be achieved by such pivotted structure.